This invention relates generally to a centrifuge apparatus and more particularly to ultracentrifuges which utilize high rotational speeds.
Swinging bucket type centrifuges include buckets, which contain the substance to be centrifuged and are supported from a rotor body by suitable supporting means. While the rotor is at rest, the bucket is generally hanging vertically downward from an appropriate bucket hanger member, and during acceleration and deceleration the buckets swing up to and down from a horizontal plane. They are restrained from outward radial movement under the high centrifugal forces by shoulder portions of the rotor which supports the buckets.
U.S. Pat. No. 3,393,864, Galasso et al., discloses a centrifuge assembly in which each bucket is supported by an independent bucket-hanger member which is spring biased toward the rotational axis of the rotor. This permits the bucket to seat in a cavity of the rotor during operation of the centrifuge. It has been discovered that under certain conditions it is possible for the rotor bucket and hanger member to twist or turn during operation. This can cause the bucket contents to mix when the centrifuge decelerates and the bucket returns to its vertical position.
U.S. Pat. No. 3,935,995, Williams et al., provides a spring biasing means similar to the means utilized by Galasso et al. The Williams arrangement also includes a bucket hanger which supports the centrifuge buckets, a compression spring and a screw which is secured in the body of the rotor. The hanger member is capable of movement in a radial direction of the rotor and is biased inwardly by the spring toward the axis of rotation of the rotor similarly as in the Galasso arrangement. The hanger member is designed to have a slidable fit within a recess formed in the rotor body itself. The hanger member is "generally square or rectangular" while the recess "also has a square or rectangular cross section to prevent the hanger from rotating about its path of movement" as it slides within the recess formed in the rotor.